研究与开发(R&D)项目评估方法的一种比较分析

过去,大量文献资料介绍了关于研究与开发(R&D)项目评估的方法,并大多集中在R&D项目评估方法得以建立的最根本的理论基础方面,很少论及方法的有效性和适应性,没有对方法的优劣和应用进行比较分析。在运用层次分析法(AHP)的基础上,对一些主要的R&D项目评估方法进行比较分析,研究了影响这些评估方法有效性的各种因素,并应用敏感性分析法确定出哪些是关键因素。     

Bancroftian filariasis in south east Madhya Pradesh: Pre-control epidemilogical observations

Lymphatic filariasis caused byWuchereria bancrofti is a major health problem next only to malaria. A study had been conducted to estimate the prevalence of microfilaraemia in a rural endemic community near Raipur. The incidence of microfilaramia in the community was found to be about 14% when studied by night finger prick method. The incidence appears to be more in males as compared to females. The infection rate in vector population i.e.,Culex quinquefasciatus was recorded at a rate of 10%. No relationship could be drawn between the rates of vector and human filarial infections or between the density of vector population and the rate of vector/human infection(s). Prior health education is essential before taking up control and preventive measures in given endemic zone.     

Community Networks: Rules of Behavior and Social Structure

This article investigates the intertwining relationships between the Gemeinschaft and the Gesellschaft dimension of a community network (CN)—that is, of a virtual community whose members' common interest is a locality, in our case the city of Milan, Italy. The article looks through the experience of the last 7 years of life on RCM—the Milan Community Network—to reflect on the role that the sharing of rules of behavior has on the evolution of social structure in a virtual community. It identifies three phases of development—the design phase, the first growth phase, and the most recent phase—and presents the social structure set up to guarantee governance of the CN. The conclusions show that the third phase is not an actual stable state, as the continuous evolution of the societal and technological context requires continuous redesign of the CN itself in order to meet the renewed demands of a new context.     

Battle-outcome-prediction conditions for variable-coefficient Lanchester-type equations for area fire2

New important battle-outcome-prediction conditions are developed for combat between two homogeneous military forces modelled by variable-coefficient Lanchester-type equations for area fire. Such conditions are very significant in modern operations research for developing important insights into the dynamics of combat. However, similar differential-equation models do arise in other fields of science and technology such as mathematical ecology and epidemiology, and consequently our new mathematical results may also find application there. These new important “simple approximate” battle-outcome-prediction conditions depend on not only the combat-attrition model but also the battle-termination model, and they are developed for two different types of battle-termination conditions (fixed-force-level-breakpoint battles and fixed-force-ratio-breakpoint battles). They are sufficient (but not necessary) to determine the outcome of battle without having to explicitly compute the force-level trajectories, and a generalization of Lanchester’s famous linear law to variable-coefficient combat is involved in their development. Certain integrability properties of the Lanchester attrition-rate coefficients figure prominently in these results, and an important physical interpretation (relating to logistics considerations) is given for these properties.     

Science,technology and regional economic development

In recent years it has become clear that a firm's competitive position is significantly influenced by its capacity to innovate. This paper explores the hypothesis that if there are factors operating at the regional level which inhibit this capacity, then firms located in particular regions may suffer. One such factor might be a lack of centralized scientific services. Regions under-represented in terms of a viable scientific infrastructure may find difficulty in attrating new science-based firms, and firms already in the region may find themselves at a comparative disavantage compared with firms located elsewhere. Social forces of this kind might be playing an important part in enhancing the social and economic problems of underdeveloped regions.     

Magnetic Field Diffusion Through Infinite Conducting Media

The diffusion of the magnetic field due to a step current in an infinitely long ideal conductor, through infinite media is discussed. An analytical solution of the field diffusion through two concentric cylinders of different conductivity is derived using a generalized Ohm's law which considers both solid and fluid conductors. A rigorous mathematical treatment which can be generalized to any number of conducting cylinders is presented.The limiting case of an external superconducting medium is discussed and it is shown that with all the other parameters fixed it represents a lower limit in diffusion time.